Gosh, I can't compete with Lesteban's answer...but I know that my friend Justin Flom once performed for like 500 prisoners in some other country. It sounds pretty crazy on paper, but from what I understand, the show went really well and everybody was really appreciative.
My friend Bizzaro was working at a restaurant opening last NYE, doing table hopping...and he did a set for David Copperfield. That's a pretty crazy gig.
And the one old guy (70? 75?) with a walker did a set (concluded with a dove inside of a change bag) at a video game bar here in Vegas (called Insert Coins)....for me, Justin Flom, Dan White, and Calen Morelli. He had no idea who he was performing for...thought we were all laymen!